在极性分子丙酮复合物CH3COCH3*H2O和非极性分子氧气的REMPI谱中,母体离子信号强度与激光偏振方向的关系是不同的.改变532 nm激光偏振方向,记录了两种分子母体离子信号强度,实验结果表明,对于氧气分子的母体离子信号强度,激光偏振方向的改变对其没有影响,而对于CH3COCH3*H2O的母体离子信号强度,随偶极矩与激光偏振方向夹角的增加,其母体离子信号强度呈余弦曲线变化,且与夹角余弦的2.1次幂成正比.理论分析显示,CH3COCH3*H2O的REMPI母体离子信号强度应与此夹角的余弦的2次幂成正比.这就说明实验结果和理论分析是相符的.

The REMPI mass spectroscopy of O_2 and CH_3COCH _3 ·H_2O displayed that the dependence of their mother ion signal intensity to la ser polarization direction is different. In the course of our experiment, chang e the polarization direction of 532 nm laser and recorder their mother ion signal intensity. The results show that the changes of laser polariz a tion have no influence to mother ion signal intensity of non-polar molecule O_ 2. And for polar molecule CH_3COCH_3·H_2O, its mother ion signal intensity c hanges with the changes of laser polarization. With the angle α of molecul ar dipo le moment to laser polarization increasing from 0° to 90°, the mother ion sig nal intensity decreases in according to cosine curve of angle α, and is in direct proportion to coa 2.1 α.Theory analysis show that mother ion intensity of CH_3COCH_3·H_2O is direct proportion to co 2.1 α. T his indicates that experimental results is well consistent with theory analysis.